Interior angles on the same side of the transversal are supplementary.

Interior angles on the same side of the transversal are supplementary.

• A. Supplementary
• B. Congruent
• C. Vertical
• D. Complementary

Answer: (A)

When two lines are cut by a transversal, the interior angles that lie between the lines on the same side of the transversal add up to 180 degrees. This sum-to-180 relationship is what “supplementary” means. So the statement describes a supplementary pair, making that term the best description. The other terms describe different ideas: congruent means equal in measure, vertical angles are opposite angles formed by intersecting lines and are equal, and complementary sums to 90 degrees.

When two lines are cut by a transversal, the interior angles that lie between the lines on the same side of the transversal add up to 180 degrees. This sum-to-180 relationship is what “supplementary” means. So the statement describes a supplementary pair, making that term the best description. The other terms describe different ideas: congruent means equal in measure, vertical angles are opposite angles formed by intersecting lines and are equal, and complementary sums to 90 degrees.